[DiogenesLamp]

Lessening the electromagnetic containment will more likely kill the reaction. Once the plasma hits the wall, it will immediately cool below the threshold required to overcome the Coulomb barrier. Of course the wall of the containment torus will experience some significant erosion.

And then the superconducting coils will blow, creating the effect of a mini-nuke.

Perhaps they will design around this probability? :)

[Fred Hayek]

Possibly there could be an electromagnetic event, whether anything like a nuke EMP is the question. When I lived in New Jersey, there were some fellow church members that had worked on the Princeton Tokamak. Plasma confinement was one of the first problems early on, and there was noticeable scoring of the torus internals due to the confinement failure. The plasma cools and game over.

Another potential problem is neutron activation of the torus materials of construction, although I associate neutron activation more with much slower thermal neutrons. Add metallurgical effects such as embrittlement, which is also noted in fission reactor pressure vessels.